Presently, magnetic tapes are used for storage, backup, archiving, and subsequent retrieval of data. Currently, data is written onto magnetic tapes in blocks separated by gaps. These gaps delimit blocks and assist in finding the beginning and ending of a particular block during read operations. Currently, data is written onto the tape in blocks with gaps in between with each starting and stopping of the data.
There are conventional approaches to set gap spacing when appending data onto tape; however, they do not eliminate or significantly reduce gaping. Further, the conventional approaches require the gaps to exist between recording blocks to provide a region for appending new data blocks and for other various reasons. Recording gaps present problems when, for example, the recording fails. Additionally, these gaps occupy media space and thus consume potential data capacity.
Other more advanced measures (e.g., interleave re-write on-the-fly recovery measures) can present a different set of gaping-related problems, particularly when appending data in mid-tape. For example, recording blocks include collective sets of smaller blocks that are grouped for error correction reasons and through advanced re-write on-the-fly techniques these collective sets get mixed up for several blocks. Thus, a problem arises when a specific record is to be located in a block to begin writing new data.
Furthermore, in conventional systems, a typical tape control system operates within the dimensions of a recording gap that is left on the tape. Also, the tape control system can position too early and overwrite the intended block that is to be appended. This complicates the tape control system, leaving behind missing data that is undetectable on a write.
FIG. 1 illustrates a prior art gaping on a tape 100. As illustrated, tape 100 includes a number of records 102, 104 that are packaged together with a leading block metadata called the header 106, 108 and a trailing block metadata called the trailer 110, 112 and placed on tape 100. Each record 102, 104 contains data that is to be saved, archived, and/or retrieved. Each head 106, 108 contains metadata to describe and/or support the data saved as records 102, 104 on tape 100. Each tail 110, 112 contains a cyclical redundancy character (CRC) which represents a numerical check on the data to determine missing or lost data by matching relevant numerical values. Such numerical check may be referred to as CRC check (CRCC). However, as illustrated, between each record 102, 104 and more specifically between head, H2, 108 and tail, T1, 110 there is the illustrated gap 114.
Such gaps 114 are present between each record 102, 104, wasting valuable space on tape 100. Furthermore, with improving technology, as the density of tapes 100 increases (e.g., smaller, but greater number of records 102, 104 are placed on tape 100), these gaps 114 are becoming proportionally larger (e.g., with respect to the size of each record 102, 104). A Gap 114 can also compromise the accuracy of records by causing bumps, overwrite and/or false start of records 102, 104. Various techniques have been used to have fewer gaps 114 (e.g., by putting more records 102, 104 on a finite tape 100 or continuous moving of tape 100 despite errors, such as with the on-the-fly technique); nevertheless, gaps 114 and gap-related problems persist. Furthermore, gaps 114 become even more complex to maintain when the recording on the tape is done in serpentine style. Serpentine refers to writing a set of tracks on one pass down a tape and later writing a next set of tracks adjacent to the previous set.